Your Facebook ads stopped converting. Maybe it happened overnight, maybe it was a slow bleed over two weeks. Either way, your first move is probably wrong.
Most people start tweaking. They change the budget, shuffle audiences, rewrite copy, turn campaigns off and on. That's guessing with extra steps. The account doesn't get better. You just run out of hypotheses and confidence at the same time.
There's a better way: diagnose before you touch anything. The problem has a source. Find it first.
Broken account vs broken creative
Before you do anything else, answer this question: are all your campaigns underperforming, or just some of them?
If everything dropped at the same time, you're probably looking at a structural issue: pixel problems, audience saturation, a policy flag on your account, or a payment hold. These affect everything.
If only certain ad sets or creatives tanked, it's more likely a creative fatigue or audience exhaustion issue. Isolated to one campaign? Almost certainly the creative or the offer.
Don't try to fix a structural problem with creative changes, and don't rebuild your entire account because one ad set burned out. Knowing which category you're in saves you days of wasted effort.
Step 1 — Check your pixel health
A broken pixel is one of the most common reasons ads underperform, and one of the most overlooked. If Facebook can't accurately attribute conversions, it can't optimize for them. The algorithm will still spend your budget. It just won't spend it well.
Go to Events Manager and check whether your key events are firing. Look for these specific problems:
- Events not firing: If your Purchase event has zero recent activity but you know sales are happening, your pixel is broken or the event isn't being called.
- Deduplication issues: If you're using both browser pixel and Conversions API, make sure deduplication is set up. Without it, Facebook counts the same purchase twice and builds the wrong optimization model.
- Mismatch between reported and actual conversions: Pull your Facebook attributed conversions and compare to your Shopify or payment processor data for the same period. A big gap means attribution is broken.
Use Facebook's Test Events tool to fire events manually and confirm they're being received. This takes ten minutes and rules out an entire category of problems.
Step 2 — Audit audience overlap and saturation
Running multiple ad sets targeting overlapping audiences means your campaigns are competing against each other in the auction. You're bidding against yourself. CPMs go up. Performance goes down.
Use the Audience Overlap tool in Ads Manager to check your active ad sets. If two audiences overlap by more than 20-30%, consolidate them or use audience exclusions.
Saturation is a separate issue. Even a non-overlapping audience can be burned out if you've been serving the same creative to the same people for weeks. Check frequency at the ad set level. If you're above 3-4 on any ad set that's underperforming, saturation is a likely contributor.
The fix for saturation isn't a new audience. It's a new creative. A fresh audience won't save a fatigued ad for long.
Step 3 — Review creative performance at the ad level
Campaign-level data lies. It averages across everything and hides what's actually happening. Go to the ad level and sort by spend. Look at CTR, cost per purchase, and ROAS for each individual creative.
You'll usually find that one or two ads are responsible for most of the spend, and their performance has quietly degraded. Everything else is either paused or spending too little to matter. The campaign looks bad because the main ad is bad, not because the whole account is.
If the winning creative from three months ago is still getting the budget, that's your culprit. Ads have a lifespan. Even the best ones burn out. For more detail on reading these signals, the guide on creative fatigue detection covers what to watch at each stage.
Step 4 — Check bid strategy and budget alignment
Budget and bid strategy mismatches are a quiet killer. If you're running a cost cap or bid cap that's set too low for your actual CPA, Facebook will either spend very slowly or not at all. You'll see low delivery paired with low results and assume the audience is the problem. It's not. Your constraints are too tight.
Similarly, if you're running CBO and one ad set is eating most of the budget, Facebook has decided that ad set is the winner. If that ad set is fatigued or wrong for your goal, the whole campaign suffers. Switch to ABO temporarily to control spend per ad set and isolate performance.
A general rule: if delivery is low and CPM is high, your bid is losing auctions. If delivery is normal but conversions are low, the problem is downstream of the click.
Step 5 — Check your landing page conversion rate
This is the step people skip, and it's often the real problem.
Pull your landing page's conversion rate from your analytics tool (Shopify analytics, Google Analytics, or your checkout platform). If CTR is reasonable but purchases are low, the drop is happening on the page, not in the ad.
Common landing page failures: slow load time on mobile, broken checkout flow, price-to-value mismatch, missing social proof, or a disconnect between what the ad promised and what the page delivers. If your ad says "50% off today only" and the page shows full price, your conversion rate will be terrible regardless of how good the ad is.
Test your own checkout on mobile. You'd be surprised how many ad accounts are losing money because nobody tested what the customer actually sees.
Common failure patterns and what they mean
- High impressions, low clicks: Creative isn't stopping the scroll. The hook is weak or the visual isn't earning attention. The audience is probably fine. See what separates bad ads from high-performance ones for a pattern-by-pattern breakdown.
- Good CTR, low conversions: The ad is attracting clicks but the landing page isn't closing. Audit the page, not the ad. Keep in mind that CTR alone doesn't tell the full story — a high CTR with low conversions often signals an audience or offer mismatch downstream.
- Rising CPMs with no creative changes: Audience saturation or policy issues. Check frequency and review your ad account's policy status.
- Erratic delivery with pauses: Payment issues, policy flags, or an account spending limit. Check your billing and account health in Business Manager.
- Performance drops after a Shopify or site change: Something broke during the update. Check your pixel, your checkout flow, and your landing page for errors.
When to reset vs rebuild
Reset when: you've identified a specific problem (broken pixel, fatigued creative, saturated audience) and can address it without touching the account structure. Most problems fall here.
Rebuild when: your account has been through multiple policy violations, your pixel history is polluted with bad data from a broken attribution period, or the account structure has become so fragmented (dozens of half-dead campaigns) that it's faster to start clean than to diagnose what's what.
If you're in a rebuild situation, don't just copy your old campaigns over. Use competitor research to find fresh angles first. Look at what ads in your market have been running for 30+ days in Spreshapp's ad browser. Those are the concepts that are working right now. Build your new account around angles that have proven staying power, not the ones you were running before they stopped working.
Once the account is healthy again and you're ready to grow spend, the guide on scaling Facebook ads without killing performance covers how to increase budget without triggering the algorithm resets that tank ROAS.
Diagnosis is always faster than guessing. Once you know what's broken, the fix is usually obvious.